I'll show you how to finish a sleeve slit on a blouse. The technique is not a novelty in the sewing blogosphere, but I haven't had a chance to see any similar tutorials written in Serbian, so I thought it wouldn't hurt to write down the instructions.

Cut the slit along the marked line, stopping the cutting approximately 5 mm away from the end of the line. Make diagonal cuts towards the endpoints of the slit, making sure you don't cut further from these points.